The Cape pangolin (Manis temminckii, ietermago) is a strange-looking armourplated ant-eating mammal that few people have ever seen in the wild, and even fewer scientists have ever studied. Jonathan Swart is among the handful of people who have devoted time to studying the Cape pangolin, working in the Sabi Sand Wildtuin adjoining the Kruger National Park.
His early research focussed on what habitats the pangolins prefer to live in, and what ant species they prefer to eat. En route to finding this out he has had a number of remarkable encounters with other animals that share the pangolin's fondness for the hours of darkness. Alone and on foot Jonathan has come face-to-face with all of the big five at night while tracking pangolins by the light of a miner's headlamp.
Jonathan's interest in pangolins began while he was studying nature conservation while working as a guide in the Sabi Sands. He has maintained his interest throughout the years, and is currently working towards his doctorate studying pangolin metabolism. For his master's degree, Jonathan managed to locate18 pangolins in the 65,000ha reserve, and he followed the daily lives of most of these for more than a year.
A few of the animals never adjusted to his observation of them, but Jonathan soon found that most would behave totally naturally if he approached them appropriately. 15 of the pangolins were fitted with radio transmitters, allowing Jonathan to find out which of their dens they were sleeping in so that he could follow them as they went in search of food.
Locating the pangolins was not easy initially, and for a frustrating four and a half months Jonathan searched for his first research subject, enlisting the aid of the guides at the lodges in the nature reserve. In a spot of lateral thinking, he also roped in the help of a police sniffer dog, which had been trained to find pangolins using a pangolin scale. When the dog was a professional pangolin scale finder, it was sent into the veld to search for the real thing. Unfortunately, the lowveld did not agree with the German shepherd.
"The dog got hayfever - it would get onto a scent and then get distracted, or start sneezing, or get hot," Jonathan says. After a week the dog and his handler returned to the big city without finding anything more than the scale used for training. But soon after that as Jonathan pulled over to resume his foot search for the elusive creatures, he saw a very young pangolin across the road. Delighted, he caught the pangolin, weighed it and fitted a radio-tracking device.
Returning to the area the next evening, he found two-forthe-price-of-one - the young pangolin he had caught the previous night was hitching a ride on its mother's back, and Jonathan was able to tag the mother as well. Two nights later guides called in a sighting of two pangolins, which turned out to be fighting, and Jonathan was able to catch them. Following the three adults led him to more pangolins and within a few months he had located most of his study animals.
Because there is so little information known about pangolins, one of the main priorities of the research was to find out what the pangolins ate and what habitats they preferred. As pangolins only eat ants and termites, Jonathan set up a number of ant traps in different places to see what ants occurred in the area, and how the seasons affected what ant species were active. Altogether, some 27,000 ants and termites walked into Jonathan's pitfall traps. 50 ant species and five termite species were identified.
By following the pangolins as they looked for food, Jonathan could collect ants from the shallow holes the pangolins dug and identify what ants the pangolins were eating. He found that one ant species made up more than threequarters of the pangolin's diet, but this species only comprised five percent of the general ant population.
Altogether, he found the pangolins ate only 15 of the ant species and all five termite species. Six species made up 98 percent of the pangolins' diet, with the other ant species being more of an occasional light snack. The pangolins' preferred meal was the ant Anoplolepis custodiens, commonly known as the pugnacious ant.
To find out what the pangolins got up to each night, Jonathan would locate where an animal was sleeping in its den, and then wait anything from a few minutes to several hours for it to come out. Once they emerged, he could follow their activities from a distance of a few metres. The pangolins usually spent three to five hours out each night looking for food, with Jonathan following in their footsteps carrying his backpack, sample bottles to collect ants, a GPS, a spotlight to blind dangerous animals, a data sheet to record observations and wearing a miner's light on his head.
He observed that the adult pangolins usually did most of their foraging at night, while the sub-adults tended tocome out earlier in the afternoon, usually about two hours before the adults. Despite being largely nocturnal, some of the pangolins would on occasion leave their dens as early as 14h30.
In the course of following the pangolins at night, Jonathan saw many leopards, some of which seemed fascinated by his presence and followed him around, showing no signs of aggression. After the first somewhat unnerving encounter, Jonathan says it was sometimes like "taking my dog for a walk". He also unintentionally walked through the middle of a breeding herd of elephants eating a midnight snack, and sometimes ran into lions.
However, one of his most treasured memories of animal encounters was with an aardvark, which walked right up to him and sniffed his legs all the way up to his knees before realising something was not quite right and bolting for the bushes. Jonathan was also able to see aardvarks and pangolins feeding side by side on a termite mound. Aardvarks are much stronger than pangolins and can dig up termites further below ground. Jonathan's measurements of pangolin diggings showed that they find most of their prey at about 4cm below the soil's surface.
They also sometimes fed from the entrance holes to ant nests, although they more commonly dug into underground ant chambers detected by their superior sense of smell. The pangolin would stick its long tubular tongue into the hole to harvest the ants, which are less active at night. Usually, the pangolin spent less than a minute at any given hole, sucking ants up before moving on.
The places that they foraged were mostly related to where the pugnacious ant was found. In the Sabi Sands, the land gently undulates in a series of hills. Usually, each hill has a sequence of different soils from the top to the bottom, which changes the types of plants that grow along the slopes of the hills. Jonathan found that while the pangolins tended to live in dens either at the top or the bottom of the hills, they usually looked for food on the hill slopes, especially those closer to the base of the hill. He believes this is related to the more structured soils with a higher clay content that are found on the hill slopes.
Different plants grow in these soils, with the pugnacious ant usually setting up home near the magic guarri (Euclea divinorum, towerghwarrie). The ants like to live near the magic guarri because sap-sucking aphid-like insects live in the tree, and the ants milk these insects for food. This illustrates nature's complex linkages, from soil to plant to insect to ant, and finally an explanation of why pangolins choose to spend their nights on the footslopes of hills.
Jonathan is now looking at how much energy a pangolin expends in its daily life, by injecting animals with a small amount of radioactively labelled water, and then taking blood samples at regular intervals to see how fast the pangolins use up the hydrogen and oxygen in the water.
He is currently looking for two more pangolins to round out his research, and so will once again be donning his miner's headlamp to go in search of the secretive creature that few people have ever been privileged to see but that Jonathan has devoted many of his nights to.
By Melissa Wray